Crank-shaft



M. 1. SCH'ENK. CRANK-SHAFT. APPLICATION FILED FEB. 27, I9l9.

Patented July 20, 1920.

UNITED STATES MARTIN J'. SCHENK, 0F CHICAGO, ILLINOIS.

GRAFIK-SHAFT.

specification of Letters Patent.

Patented July 20, 1920.

Applicationled February 27, 1919. Serial No. 279,529.

To all whom it may concern:

Be it known that I, MARTIN J. SGHENK, a citizen of the United States, residing .at Chicago, in the county of Cook and State of Illinois, have invented certain new and useful Improvements in Crank-Shafts, of which the following is a specification.

This invention relates to improvements in crank shafts and the bearings associated therewith.

One object of the invention is to provide a crank shaft which shall be made up of a plurality of detachable parts, any one of which may be readily and quickly removed should repairs or replacement become necessary, thereby dispensing with the removal of the entire crank shaft and the many disadvantages incident thereto, and also avoiding the expense of replacing the entire crank shaft such as is now occasioned in internal combustion engines wherein solid crank shafts are `used when such crank shafts become worn beyond repair, fractured, or otherwise rendered inoperative.

Another object of the invention resides in the provision of a novel form of adjustable antifriction bearing for crank shafts and for the connecting rods attached thereto.

A further object is to provide a crank shaft living detachable crank pins, whereby the same may be readily and quickly removed, together with the attached connecting rods and pistons, independently of the crank shaft as a whole.

Other objects and advantages will become apparent from the following description, taken in connection with the accompanying drawings, wherein one form of the invention is illustrated.

Figure 1 is a vertical sectional view taken through the crank case of an internal combustion engine, showing my improved crank shaft mounted in operative position therein;

Fig. 2 is a sectional view taken on the line 2-2 of Fig. 1;

Fig. 3 is a detailed view, partly in section, showing the application of my invention to an internal combustion engine of the V-type and used in the propulsion of vehicles, aeroplanes, and the like, but it will be obvious from the following that the invention is not limited in scope to such use, but, on the other hand, may be used substantially where any crank shaft is employed. In Fig. 1 of the drawings a crank shaft, constructed in accordance with the present invention, is shown mounted in operative position within the crank case of an internal combustion engine, the crank case being broken away, as shown, in order to indicate that as many cranks may be provided on the shaft as desired, depending, of course, upon the number of cylinders provided in the particular engine in connection with which it is desired to use the shaft. In this gure of the drawings, only two cranks are shown in order to simplify the illustration.

Referring more in detail to the drawings, the crank case is shown at 10, and preferably comprises an upper section 10a apertured across the top to permit of the pistons extending upwardly into their respective cylinders, and a lower section 1()b which is secured in any suitable manner to the section 10a and which forms with said section 10a a complete housing for the crank shaft and associated parts.

The crank shaft is illustrated at 11, and is shown supported by three main bearings 12, one provided in each end of the crank case, and one interposed centrally between the two ends of the crank case, substantially as shown. The crank shaft 11 preferably comprises a plurality of main shaft sections 13 to the adjacent ends of which are attached removable crank arms 11. Each of the crank arms is provided with two oppositely disposed transverse V-shaped channels 15 and 16, the channel 15 being designed to receive one end of one of the main shaft sections 13, said section being clamped securely within said channel by means of the retaining block 17 and screw-threaded bolts 18. The end of the shaft section 13, which isfthus clamped within the channel 15, is preferably provided with oppositely disposed grooves 19, through which the bolts 18 extend when placed in position. The ends'of the bolts preferably screw-threadedly engage the crank'arm 14, and in addition are provided with nuts 20. In order that the grooves 19 provided in the end of the shaft section 13 may aline properly with the bolt holes provided in the crank arm 14 andthe clamping block V17 when said shaft opposite face of the crank arm 14 is located adjacent the end of the .crank arm opposite to the end in which the channel 15 is provided, and is adapted to receive the end of thel crank pin 22, said crank ,pin being clamped securely in position within; the channel 16 in substantially the same manner as the shaft section 13 is clamped within its channel 15, namely, by means of a clamping block 23 and bolts 24, the bolts 24 screwthreadedly engaging the crank arm 14 and extending through oppositely disposed grooves 25 provided' in the pin 22. A dowel pin 21EL is also provided, so that the pin 22 may be positioned within the channel 16 in such wise that the grooves 25 aline properly with the bolt holes provided in the block 23 and crank arm 14. The two crank arms of each of the cranks of the crank shaft are attached at their opposite ends,respectively, to the ends of the crank pin 22, which is common to said crank arms, and to the adjacent ends of the corresponding shaft sections in the manner above set out. It will be readily observed that by providing the channels 15 and 16 of the crank arm 14 in opposite faces thereof that the turning stresses imparted to the crank shaft by the connecting rod yare transmitted directly to the shaft through the crank arm. In other words, the channels are so arranged that upon a forward driving of the shaft, the turning moments are applied directly to the crank arm, as distinguished from an application thereof in the reverse direction which would bring the force thereof to bear against the clamping blocks 17 and 23.

'The connectingrods, shown at 26, are preferably constructed integral, the lower ends thereof being enlarged, as shown at 27, and bein provided with an opening extending terethrough, through which openings the corresponding crank pins 22 are adapted to extend. The openings provided in the enlarged lower ends 27 of the connecting rods are of larger diameter than the diameter of the crank pins, so that an interposed housing is provided for the antifriction bearings. These bearings each comprise an inner and outer raceway 28 and 29, respectively, the outer raceway 29 comprising a' plurality of conically tapered rings 30 fixed within the opening provided in the enlarged end 27 of the connecting rod, while the inner raceway comprises a plurality of similarly tapered rings 31 whichfare mounted on the crank pin 22 and adapted to rotate therewith. Interposed between the two raceways 28 and'29 are a plurality of doubly tapered roller bearings 32, preferably in the form of double truncated cones, the opposite ends of each of these roller bearings extending between a pair of the rings 30 and 31. A suitable spacing element 33, similar to the squirrel cage commonly provided in anti-friction bearings, is provided in the present bearing in order to maintain the rollers 32 properly spaced apart. The enlarged end 27 of the connecting rod is preferably provided with an overhanging fiange 34, designed to maintain the raceway 29 against lateral displacement in one direction, while at the other side of the head 27 a removable locking ring 35 is provided, designed to maintain the raceway 29 thereto, and suitable nuts 36v are provided,`

whereby the bearing and connecting rodl may be properly centered on the pin by moving the same longitudinally thereof. From this construction, it will also be observed that should the bearings become worn, the same may be readily and quickly tightened up by merely adjusting the nuts 36 4toward each other, thus' forcing the rings 31 of the raceway 28 inwardly and thereby wedging the roller bearings 32 into firm engagement between said rings 31 and the rings 30 forming the outer raceway 29. It is preferred to provide some suitable locking means, such as shown at 37, for the nuts 36. On the lower side of the enlarged end 27 of each of the connecting rods is provided an oil dip 38, by means of which oil is scooped from the bottom of the crank case during each revolution of the shaft and conveyed from the dip 38 upwardly through the duct 39 to the bearing. v

The main center bearing 12 is the same in construction as the connecting rod bearings just described, and accordingly the description of the latter applies equally as well to the former. As will be observed from Fig. 1 of the drawings, this center main bearing is contained within the housing 40, which housing is suspended from the top wall of the crank case section 10, as shown. The two end main bearings are also of the same construction as the connecting rod bearings,

l:amarre with the exceptionl that only one adjusting nut 41 is provided. It will be observed, however, that an adjustment of the rings of the inner raceway 28 of these bearings may be effected by the adjusting nut 41 to compensate for any wear that may take place in substantially the same manner in which an adjustment of the connecting rod bearings is effected. On the inner side of each of these main end bearings, there is provided a suitable spacing element 42 against which the adjacent crank arm bears. The housing for each of these main bearings is, as with the connecting rod bearings, provided with an integral retaining flange 43 and a removable locking ring 44.

In Fig. 3 of the drawings is shown a detailed fragmentary view, partly in section, disclosing the method of adapting a crank shaft constructed in accordance with the present invention for use in connection with internal combustion engines of the so-called V-type. In this view, one crank of the shaft is shown and two connecting rods, one from each of the corresponding cylinders of the adjacent series attached to the crank pin of said crank, a bearing of the type hereinbefore described being provided for each of the connecting rods, and a suitable spacing element 45 being interposed betweenA the bearings substantially as shown. The bearings in this construction are the same as ,j those .hereinbefore described, and are adjustableby means of the nuts 46, by means of which nuts the connecting rods may also be properly centered relatively to their respective cylinders.

From the foregoing, it will be observed that a multiple section crank shaft has been provided which may be readily assembled i and disassembled, and one which permits of any one of its various parts being readily and quickly removed for purposes of repair or replacement. It will be further observed that in the event it is desired for any reason to remove `one of the connecting rods, to-

gether with *he piston attached thereto, that such removal may be effected by merely removing the lower section 10,bof the crank case and then removing the bolts 24 and clamping block 23 at each end of the crank pin, after which the crank pin, bearing, connecting rod and piston may be quickly and entirely removed from the engine as a unit. It will also be observed that should the bearings, after long continued use, become worn to any degree that by merely removing the lower section 10b of the crank case said bearings may be quickly adjusted, so as to compensate for such 4wear by merely tightening up on the adjusting nuts 36. This adjustable feature, as above pointed out and as is apparent from the drawings, is also present in each of the main bearings of the crank shaft, and, accordingly., these bearings may also be adjusted to compensate for any wear which may occur. It will also be apparent from the multiple section construction of the crank shaft, and particularly from tho construction of the crank arms, that any one of the cranks of the shaft may be entirely removed without interfering with or disassembling any of the other portions of the crank shaft. In other words, all of the parts of the shaft are quickly removable and readily replaceable, so that if, due to various reasons, a partof the shaft is rendered useless, such part and such part only need be replaced in order to render the crank shaft again operable. It will be further noted that by reason of the anti-friction bearings, herein described, that wear upon the main shaft sections and the crank pins, as well as on the connecting rods and crank case, is completely avoided, and that by reason of the quickly removable nature of the bearings the same, should they become broken or otherwise rendered inoperative, may be quickly replaced without necessitating a removal of anything from the structure but the bearing which it is desired to replace. In View of the above, the many advantages of the present construction over crank shafts as heretofore constructed will be apparent.

It is obvious that various changes and modifications may be made in the particular embodiment of the invention herein illustrated without departing from the spirit of the invention, and it is not therefore desired to limit the invention to such embodiment or to the particular adaptation ofthe embodiment shown in the drawings, except where limitations appear in the appended claims.

What I claim is:

1. In combination, a crank shaft having a detachable crank pin, a connecting rod attached to said pin, and means for laterally adjusting said connecting rod on said pin in either direction.

2. A crank shaft comprising a plurality said horizontal portion of said crank adja- 'f cent said first raceway, roller bearings interposed between said raceways, means carried by said connecting rod for maintaining said first raceway against accidental displacement, and adjustable means on the said horizontal portion of said crank in engagement with said second raceway, whereby said bearing, together with said connecting rod, may be adjusted longitudinally of said horizontal portion.

4. A crank shaft comprising a plurality of main shaft sections, a crank pin, crank arms having channels formed in the opposite faces thereof and adjacent the ends thereof adapted to receive the adjacent ends of said shaft sections and the ends of said pin, re-

spectively, vand means for clamping said crank arms in operative position.

5. A crank shaft comprising a lurality of main shaft sections, a crank pin, -shapedcrank arms adapted to receive within their oppositely disposed channels the ends of said pin and the adjacent ends of said sections, respectively, and clamping blocks detachably secured in said channels for holding said arms in operative position, said arms being mounted in such wise that the forward driving thrusts imparted thereto through said pin are applied directly against said arms in the direction of the pinreceiving channels, whereby undue strain on said blocks is avoided.

In testimony whereof I have subscribed my name. v MARTIN J. SCHENK. 

